1643800542690 has 64 divisors (see below), whose sum is σ = 4178251766016. Its totient is φ = 412456568832.

The previous prime is 1643800542679. The next prime is 1643800542697. The reversal of 1643800542690 is 962450083461.

It is a super-2 number, since 2×1643800542690² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1643800542697) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1602214 + ... + 2419646.

It is an arithmetic number, because the mean of its divisors is an integer number (65285183844).

Almost surely, 2^{1643800542690} is an apocalyptic number.

1643800542690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1643800542690 is an abundant number, since it is smaller than the sum of its proper divisors (2534451223326).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1643800542690 is a wasteful number, since it uses less digits than its factorization.

1643800542690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 821403.

The product of its (nonzero) digits is 1244160, while the sum is 48.

The spelling of 1643800542690 in words is "one trillion, six hundred forty-three billion, eight hundred million, five hundred forty-two thousand, six hundred ninety".